RELIABILITY
Defintion
The extent to which a measure is consistent
replicability
standardization
Reliability in Experiments
Reliability in Observations
Reliability in Interviews
Reliability in Questionnaires / Tests
can't repeat if the IV is a historical event or if the previous study was too unethical
standardized procedure --> allows another researcher to repeat the experiment to see if the results are consistent
inter-rater/observer reliability - the extent to which 2 observers record the same behavior in the same way
can be improved by agreeing on what fits into each category (having operationalized definitions) before the observation begins
Inter-interviewer reliability - the extent to which 2 interviewers interpret the same participant's responses in the same way
Internal reliability
There is a possibility for subjective questions to lack reliability
because one person's definition of 'agree' on a likert scale may be inconsistent with another person's interpretation of the word 'agree'
External reliability
Split halves technique - looks to find out if scores on the first half of the test are the same as scores on the second half of the test
allows us to know whether the test is internally consistent (measures the same factor from start to finish)
Test-retest reliability - the extent to which scores on a test are similar when Ps are tested on the same measure at multiple points in time